1 //===--- StmtCXX.h - Classes for representing C++ statements ----*- C++ -*-===//
3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
4 // See https://llvm.org/LICENSE.txt for license information.
5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
7 //===----------------------------------------------------------------------===//
9 // This file defines the C++ statement AST node classes.
11 //===----------------------------------------------------------------------===//
13 #ifndef LLVM_CLANG_AST_STMTCXX_H
14 #define LLVM_CLANG_AST_STMTCXX_H
16 #include "clang/AST/DeclarationName.h"
17 #include "clang/AST/Expr.h"
18 #include "clang/AST/NestedNameSpecifier.h"
19 #include "clang/AST/Stmt.h"
20 #include "llvm/Support/Compiler.h"
26 /// CXXCatchStmt - This represents a C++ catch block.
28 class CXXCatchStmt : public Stmt {
29 SourceLocation CatchLoc;
30 /// The exception-declaration of the type.
31 VarDecl *ExceptionDecl;
32 /// The handler block.
36 CXXCatchStmt(SourceLocation catchLoc, VarDecl *exDecl, Stmt *handlerBlock)
37 : Stmt(CXXCatchStmtClass), CatchLoc(catchLoc), ExceptionDecl(exDecl),
38 HandlerBlock(handlerBlock) {}
40 CXXCatchStmt(EmptyShell Empty)
41 : Stmt(CXXCatchStmtClass), ExceptionDecl(nullptr), HandlerBlock(nullptr) {}
43 SourceLocation getBeginLoc() const LLVM_READONLY { return CatchLoc; }
44 SourceLocation getEndLoc() const LLVM_READONLY {
45 return HandlerBlock->getEndLoc();
48 SourceLocation getCatchLoc() const { return CatchLoc; }
49 VarDecl *getExceptionDecl() const { return ExceptionDecl; }
50 QualType getCaughtType() const;
51 Stmt *getHandlerBlock() const { return HandlerBlock; }
53 static bool classof(const Stmt *T) {
54 return T->getStmtClass() == CXXCatchStmtClass;
57 child_range children() { return child_range(&HandlerBlock, &HandlerBlock+1); }
59 const_child_range children() const {
60 return const_child_range(&HandlerBlock, &HandlerBlock + 1);
63 friend class ASTStmtReader;
66 /// CXXTryStmt - A C++ try block, including all handlers.
68 class CXXTryStmt final : public Stmt,
69 private llvm::TrailingObjects<CXXTryStmt, Stmt *> {
71 friend TrailingObjects;
72 friend class ASTStmtReader;
74 SourceLocation TryLoc;
76 size_t numTrailingObjects(OverloadToken<Stmt *>) const { return NumHandlers; }
78 CXXTryStmt(SourceLocation tryLoc, Stmt *tryBlock, ArrayRef<Stmt*> handlers);
79 CXXTryStmt(EmptyShell Empty, unsigned numHandlers)
80 : Stmt(CXXTryStmtClass), NumHandlers(numHandlers) { }
82 Stmt *const *getStmts() const { return getTrailingObjects<Stmt *>(); }
83 Stmt **getStmts() { return getTrailingObjects<Stmt *>(); }
86 static CXXTryStmt *Create(const ASTContext &C, SourceLocation tryLoc,
87 Stmt *tryBlock, ArrayRef<Stmt*> handlers);
89 static CXXTryStmt *Create(const ASTContext &C, EmptyShell Empty,
90 unsigned numHandlers);
92 SourceLocation getBeginLoc() const LLVM_READONLY { return getTryLoc(); }
94 SourceLocation getTryLoc() const { return TryLoc; }
95 SourceLocation getEndLoc() const {
96 return getStmts()[NumHandlers]->getEndLoc();
99 CompoundStmt *getTryBlock() {
100 return cast<CompoundStmt>(getStmts()[0]);
102 const CompoundStmt *getTryBlock() const {
103 return cast<CompoundStmt>(getStmts()[0]);
106 unsigned getNumHandlers() const { return NumHandlers; }
107 CXXCatchStmt *getHandler(unsigned i) {
108 return cast<CXXCatchStmt>(getStmts()[i + 1]);
110 const CXXCatchStmt *getHandler(unsigned i) const {
111 return cast<CXXCatchStmt>(getStmts()[i + 1]);
114 static bool classof(const Stmt *T) {
115 return T->getStmtClass() == CXXTryStmtClass;
118 child_range children() {
119 return child_range(getStmts(), getStmts() + getNumHandlers() + 1);
122 const_child_range children() const {
123 return const_child_range(getStmts(), getStmts() + getNumHandlers() + 1);
127 /// CXXForRangeStmt - This represents C++0x [stmt.ranged]'s ranged for
128 /// statement, represented as 'for (range-declarator : range-expression)'
129 /// or 'for (init-statement range-declarator : range-expression)'.
131 /// This is stored in a partially-desugared form to allow full semantic
132 /// analysis of the constituent components. The original syntactic components
133 /// can be extracted using getLoopVariable and getRangeInit.
134 class CXXForRangeStmt : public Stmt {
135 SourceLocation ForLoc;
136 enum { INIT, RANGE, BEGINSTMT, ENDSTMT, COND, INC, LOOPVAR, BODY, END };
137 // SubExprs[RANGE] is an expression or declstmt.
138 // SubExprs[COND] and SubExprs[INC] are expressions.
140 SourceLocation CoawaitLoc;
141 SourceLocation ColonLoc;
142 SourceLocation RParenLoc;
144 friend class ASTStmtReader;
146 CXXForRangeStmt(Stmt *InitStmt, DeclStmt *Range, DeclStmt *Begin,
147 DeclStmt *End, Expr *Cond, Expr *Inc, DeclStmt *LoopVar,
148 Stmt *Body, SourceLocation FL, SourceLocation CAL,
149 SourceLocation CL, SourceLocation RPL);
150 CXXForRangeStmt(EmptyShell Empty) : Stmt(CXXForRangeStmtClass, Empty) { }
152 Stmt *getInit() { return SubExprs[INIT]; }
153 VarDecl *getLoopVariable();
154 Expr *getRangeInit();
156 const Stmt *getInit() const { return SubExprs[INIT]; }
157 const VarDecl *getLoopVariable() const;
158 const Expr *getRangeInit() const;
161 DeclStmt *getRangeStmt() { return cast<DeclStmt>(SubExprs[RANGE]); }
162 DeclStmt *getBeginStmt() {
163 return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
165 DeclStmt *getEndStmt() { return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]); }
166 Expr *getCond() { return cast_or_null<Expr>(SubExprs[COND]); }
167 Expr *getInc() { return cast_or_null<Expr>(SubExprs[INC]); }
168 DeclStmt *getLoopVarStmt() { return cast<DeclStmt>(SubExprs[LOOPVAR]); }
169 Stmt *getBody() { return SubExprs[BODY]; }
171 const DeclStmt *getRangeStmt() const {
172 return cast<DeclStmt>(SubExprs[RANGE]);
174 const DeclStmt *getBeginStmt() const {
175 return cast_or_null<DeclStmt>(SubExprs[BEGINSTMT]);
177 const DeclStmt *getEndStmt() const {
178 return cast_or_null<DeclStmt>(SubExprs[ENDSTMT]);
180 const Expr *getCond() const {
181 return cast_or_null<Expr>(SubExprs[COND]);
183 const Expr *getInc() const {
184 return cast_or_null<Expr>(SubExprs[INC]);
186 const DeclStmt *getLoopVarStmt() const {
187 return cast<DeclStmt>(SubExprs[LOOPVAR]);
189 const Stmt *getBody() const { return SubExprs[BODY]; }
191 void setInit(Stmt *S) { SubExprs[INIT] = S; }
192 void setRangeInit(Expr *E) { SubExprs[RANGE] = reinterpret_cast<Stmt*>(E); }
193 void setRangeStmt(Stmt *S) { SubExprs[RANGE] = S; }
194 void setBeginStmt(Stmt *S) { SubExprs[BEGINSTMT] = S; }
195 void setEndStmt(Stmt *S) { SubExprs[ENDSTMT] = S; }
196 void setCond(Expr *E) { SubExprs[COND] = reinterpret_cast<Stmt*>(E); }
197 void setInc(Expr *E) { SubExprs[INC] = reinterpret_cast<Stmt*>(E); }
198 void setLoopVarStmt(Stmt *S) { SubExprs[LOOPVAR] = S; }
199 void setBody(Stmt *S) { SubExprs[BODY] = S; }
201 SourceLocation getForLoc() const { return ForLoc; }
202 SourceLocation getCoawaitLoc() const { return CoawaitLoc; }
203 SourceLocation getColonLoc() const { return ColonLoc; }
204 SourceLocation getRParenLoc() const { return RParenLoc; }
206 SourceLocation getBeginLoc() const LLVM_READONLY { return ForLoc; }
207 SourceLocation getEndLoc() const LLVM_READONLY {
208 return SubExprs[BODY]->getEndLoc();
211 static bool classof(const Stmt *T) {
212 return T->getStmtClass() == CXXForRangeStmtClass;
216 child_range children() {
217 return child_range(&SubExprs[0], &SubExprs[END]);
220 const_child_range children() const {
221 return const_child_range(&SubExprs[0], &SubExprs[END]);
225 /// Representation of a Microsoft __if_exists or __if_not_exists
226 /// statement with a dependent name.
228 /// The __if_exists statement can be used to include a sequence of statements
229 /// in the program only when a particular dependent name does not exist. For
233 /// template<typename T>
234 /// void call_foo(T &t) {
235 /// __if_exists (T::foo) {
236 /// t.foo(); // okay: only called when T::foo exists.
241 /// Similarly, the __if_not_exists statement can be used to include the
242 /// statements when a particular name does not exist.
244 /// Note that this statement only captures __if_exists and __if_not_exists
245 /// statements whose name is dependent. All non-dependent cases are handled
246 /// directly in the parser, so that they don't introduce a new scope. Clang
247 /// introduces scopes in the dependent case to keep names inside the compound
248 /// statement from leaking out into the surround statements, which would
249 /// compromise the template instantiation model. This behavior differs from
250 /// Visual C++ (which never introduces a scope), but is a fairly reasonable
251 /// approximation of the VC++ behavior.
252 class MSDependentExistsStmt : public Stmt {
253 SourceLocation KeywordLoc;
255 NestedNameSpecifierLoc QualifierLoc;
256 DeclarationNameInfo NameInfo;
259 friend class ASTReader;
260 friend class ASTStmtReader;
263 MSDependentExistsStmt(SourceLocation KeywordLoc, bool IsIfExists,
264 NestedNameSpecifierLoc QualifierLoc,
265 DeclarationNameInfo NameInfo,
266 CompoundStmt *SubStmt)
267 : Stmt(MSDependentExistsStmtClass),
268 KeywordLoc(KeywordLoc), IsIfExists(IsIfExists),
269 QualifierLoc(QualifierLoc), NameInfo(NameInfo),
270 SubStmt(reinterpret_cast<Stmt *>(SubStmt)) { }
272 /// Retrieve the location of the __if_exists or __if_not_exists
274 SourceLocation getKeywordLoc() const { return KeywordLoc; }
276 /// Determine whether this is an __if_exists statement.
277 bool isIfExists() const { return IsIfExists; }
279 /// Determine whether this is an __if_exists statement.
280 bool isIfNotExists() const { return !IsIfExists; }
282 /// Retrieve the nested-name-specifier that qualifies this name, if
284 NestedNameSpecifierLoc getQualifierLoc() const { return QualifierLoc; }
286 /// Retrieve the name of the entity we're testing for, along with
287 /// location information
288 DeclarationNameInfo getNameInfo() const { return NameInfo; }
290 /// Retrieve the compound statement that will be included in the
291 /// program only if the existence of the symbol matches the initial keyword.
292 CompoundStmt *getSubStmt() const {
293 return reinterpret_cast<CompoundStmt *>(SubStmt);
296 SourceLocation getBeginLoc() const LLVM_READONLY { return KeywordLoc; }
297 SourceLocation getEndLoc() const LLVM_READONLY {
298 return SubStmt->getEndLoc();
301 child_range children() {
302 return child_range(&SubStmt, &SubStmt+1);
305 const_child_range children() const {
306 return const_child_range(&SubStmt, &SubStmt + 1);
309 static bool classof(const Stmt *T) {
310 return T->getStmtClass() == MSDependentExistsStmtClass;
314 /// Represents the body of a coroutine. This wraps the normal function
315 /// body and holds the additional semantic context required to set up and tear
316 /// down the coroutine frame.
317 class CoroutineBodyStmt final
319 private llvm::TrailingObjects<CoroutineBodyStmt, Stmt *> {
321 Body, ///< The body of the coroutine.
322 Promise, ///< The promise statement.
323 InitSuspend, ///< The initial suspend statement, run before the body.
324 FinalSuspend, ///< The final suspend statement, run after the body.
325 OnException, ///< Handler for exceptions thrown in the body.
326 OnFallthrough, ///< Handler for control flow falling off the body.
327 Allocate, ///< Coroutine frame memory allocation.
328 Deallocate, ///< Coroutine frame memory deallocation.
329 ReturnValue, ///< Return value for thunk function: p.get_return_object().
330 ResultDecl, ///< Declaration holding the result of get_return_object.
331 ReturnStmt, ///< Return statement for the thunk function.
332 ReturnStmtOnAllocFailure, ///< Return statement if allocation failed.
333 FirstParamMove ///< First offset for move construction of parameter copies.
337 friend class ASTStmtReader;
338 friend class ASTReader;
339 friend TrailingObjects;
341 Stmt **getStoredStmts() { return getTrailingObjects<Stmt *>(); }
343 Stmt *const *getStoredStmts() const { return getTrailingObjects<Stmt *>(); }
348 Stmt *Body = nullptr;
349 Stmt *Promise = nullptr;
350 Expr *InitialSuspend = nullptr;
351 Expr *FinalSuspend = nullptr;
352 Stmt *OnException = nullptr;
353 Stmt *OnFallthrough = nullptr;
354 Expr *Allocate = nullptr;
355 Expr *Deallocate = nullptr;
356 Expr *ReturnValue = nullptr;
357 Stmt *ResultDecl = nullptr;
358 Stmt *ReturnStmt = nullptr;
359 Stmt *ReturnStmtOnAllocFailure = nullptr;
360 ArrayRef<Stmt *> ParamMoves;
365 CoroutineBodyStmt(CtorArgs const& Args);
368 static CoroutineBodyStmt *Create(const ASTContext &C, CtorArgs const &Args);
369 static CoroutineBodyStmt *Create(const ASTContext &C, EmptyShell,
372 bool hasDependentPromiseType() const {
373 return getPromiseDecl()->getType()->isDependentType();
376 /// Retrieve the body of the coroutine as written. This will be either
377 /// a CompoundStmt or a TryStmt.
378 Stmt *getBody() const {
379 return getStoredStmts()[SubStmt::Body];
382 Stmt *getPromiseDeclStmt() const {
383 return getStoredStmts()[SubStmt::Promise];
385 VarDecl *getPromiseDecl() const {
386 return cast<VarDecl>(cast<DeclStmt>(getPromiseDeclStmt())->getSingleDecl());
389 Stmt *getInitSuspendStmt() const {
390 return getStoredStmts()[SubStmt::InitSuspend];
392 Stmt *getFinalSuspendStmt() const {
393 return getStoredStmts()[SubStmt::FinalSuspend];
396 Stmt *getExceptionHandler() const {
397 return getStoredStmts()[SubStmt::OnException];
399 Stmt *getFallthroughHandler() const {
400 return getStoredStmts()[SubStmt::OnFallthrough];
403 Expr *getAllocate() const {
404 return cast_or_null<Expr>(getStoredStmts()[SubStmt::Allocate]);
406 Expr *getDeallocate() const {
407 return cast_or_null<Expr>(getStoredStmts()[SubStmt::Deallocate]);
409 Expr *getReturnValueInit() const {
410 return cast<Expr>(getStoredStmts()[SubStmt::ReturnValue]);
412 Stmt *getResultDecl() const { return getStoredStmts()[SubStmt::ResultDecl]; }
413 Stmt *getReturnStmt() const { return getStoredStmts()[SubStmt::ReturnStmt]; }
414 Stmt *getReturnStmtOnAllocFailure() const {
415 return getStoredStmts()[SubStmt::ReturnStmtOnAllocFailure];
417 ArrayRef<Stmt const *> getParamMoves() const {
418 return {getStoredStmts() + SubStmt::FirstParamMove, NumParams};
421 SourceLocation getBeginLoc() const LLVM_READONLY {
422 return getBody() ? getBody()->getBeginLoc()
423 : getPromiseDecl()->getBeginLoc();
425 SourceLocation getEndLoc() const LLVM_READONLY {
426 return getBody() ? getBody()->getEndLoc() : getPromiseDecl()->getEndLoc();
429 child_range children() {
430 return child_range(getStoredStmts(),
431 getStoredStmts() + SubStmt::FirstParamMove + NumParams);
434 const_child_range children() const {
435 return const_child_range(getStoredStmts(), getStoredStmts() +
436 SubStmt::FirstParamMove +
440 static bool classof(const Stmt *T) {
441 return T->getStmtClass() == CoroutineBodyStmtClass;
445 /// Represents a 'co_return' statement in the C++ Coroutines TS.
447 /// This statament models the initialization of the coroutine promise
448 /// (encapsulating the eventual notional return value) from an expression
449 /// (or braced-init-list), followed by termination of the coroutine.
451 /// This initialization is modeled by the evaluation of the operand
452 /// followed by a call to one of:
453 /// <promise>.return_value(<operand>)
454 /// <promise>.return_void()
455 /// which we name the "promise call".
456 class CoreturnStmt : public Stmt {
457 SourceLocation CoreturnLoc;
459 enum SubStmt { Operand, PromiseCall, Count };
460 Stmt *SubStmts[SubStmt::Count];
464 friend class ASTStmtReader;
466 CoreturnStmt(SourceLocation CoreturnLoc, Stmt *Operand, Stmt *PromiseCall,
467 bool IsImplicit = false)
468 : Stmt(CoreturnStmtClass), CoreturnLoc(CoreturnLoc),
469 IsImplicit(IsImplicit) {
470 SubStmts[SubStmt::Operand] = Operand;
471 SubStmts[SubStmt::PromiseCall] = PromiseCall;
474 CoreturnStmt(EmptyShell) : CoreturnStmt({}, {}, {}) {}
476 SourceLocation getKeywordLoc() const { return CoreturnLoc; }
478 /// Retrieve the operand of the 'co_return' statement. Will be nullptr
479 /// if none was specified.
480 Expr *getOperand() const { return static_cast<Expr*>(SubStmts[Operand]); }
482 /// Retrieve the promise call that results from this 'co_return'
483 /// statement. Will be nullptr if either the coroutine has not yet been
484 /// finalized or the coroutine has no eventual return type.
485 Expr *getPromiseCall() const {
486 return static_cast<Expr*>(SubStmts[PromiseCall]);
489 bool isImplicit() const { return IsImplicit; }
490 void setIsImplicit(bool value = true) { IsImplicit = value; }
492 SourceLocation getBeginLoc() const LLVM_READONLY { return CoreturnLoc; }
493 SourceLocation getEndLoc() const LLVM_READONLY {
494 return getOperand() ? getOperand()->getEndLoc() : getBeginLoc();
497 child_range children() {
499 return child_range(SubStmts + SubStmt::PromiseCall,
500 SubStmts + SubStmt::Count);
501 return child_range(SubStmts, SubStmts + SubStmt::Count);
504 const_child_range children() const {
506 return const_child_range(SubStmts + SubStmt::PromiseCall,
507 SubStmts + SubStmt::Count);
508 return const_child_range(SubStmts, SubStmts + SubStmt::Count);
511 static bool classof(const Stmt *T) {
512 return T->getStmtClass() == CoreturnStmtClass;
516 } // end namespace clang